Geoff Ogilvy took a three-point lead going into the final round of the Barracuda Championship in Reno.
The Australian had seven birdies and two bogeys in a third round which netted him 12 points under the modified Stableford scoring system.
Players receive eight points for an albatross, five for an eagle, two for a birdie, nothing for a par, minus-one for a bogey and minus-three for a double bogey or worse.
Ogilvy's efforts took him to 35 points after three rounds, edging him ahead of overnight leader Nick Watney who could manage only six points on the day.
Watney shares second with the charging Jason Allred, who racked up 14 points from six birdies, an eagle and three bogeys.
Ogilvy told pgatour.com: "I played quite well, birdied the par-fives I needed to birdie, which is ante in this format because birdies are so much better than bogeys are bad.
"It's definitely a format that rewards the guy that makes a lot of birdies. So I put some points on the board, which you have to, because there were some low ones this morning, it looked like - or some high ones, however you want to put it."
The consistent Brendon Steele is fourth after rounds worth nine, 11 and 10 points while John Mallinger made a superb surge into a share of fifth place on 28 points.
Mallinger's 19-point third round was a record for the event and featured a hole in one at the par-three 11th and seven birdies, moving him level with Lee Janzen and David Lingmerth.
As well as being worth five points in the tournament, Mallinger's ace saw him win a new car - though he was relying on the crowd's reaction for that information.
"You can't see, it's (an elevated green)," he said. "I hit it. They all clapped. I was like, 'Is it close? Is that in?' ... Sounds like I got a Lexus."
Ireland's Padraig Harrington is tied for 37th place, 16 points off the lead.